Method of forming can parts



March 16, 1943- J. M. HOTHERSALL METHOD OF FORMING CAN PARTS Filed May 2l, 1940 Patented Miele, 1943 METHOD F NBMING CAN PARTS John M. nainemu, Brooklyn. N. Y., minor to American Can Company, New York, N. Y., a corporation of Jene IApplication May 21, 1940, Serial No. 338,455

2 Claims. .(Cl. 15S-48M The present invention relates to a method of forming container or can parts and has particular reference to producing closely spaced bead or thread sections in can parts.

In the manufacture of sheet metal can parts, such as can bodies, can covers, collars, and the like it is often desired to have thread sections closely adjacent a bead section. In some cases two bead sections may be required in close proximity. One bead section may'extend outwardly while the other may extend inwardly. In any case the forming of such bead or thread sections when closely spaced is a dlilicult matter to effect without rupturing the metal from which the can part is made. Such bead forming usually requires a number of operations.

The instant invention contemplates overcoming this diillculty by a method of forming such bead or thread sections in one operation by partially drawing the metal of the can part from one section thereof for one bead and actually drawing the metal from another section for another bead, thus preventing rupture of the metal between the beads.

An object of the invention, therefore, is the section being operated upon, parts being broken away; and

Fig. 5 is a transverse sectional view taken substantially along the line 5 5 in Fig. 3. As a preferred embodiment of the instant invention the drawing illustrates a cylindrical sheet -..metal can body A being formed with an inwardly I provision of a method of forming closely adjacent bead protuberances in sheet metal in one opera- .tion wherein a portion of the metal for one bead metal between the protuberances.

Another object is the provision of such a method of forming bead protuberances wherein one bead protuberance may be formed inwardly and another outwardly in the same operation.

Another object is the provision of such a method of forming bead protuberances wherein a plurality of closely spaced bead protuberances or thread protuberances may be formed in one operation.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawing, discloses a preferred embodiment thereof.

Referring to the drawing:

Figures l, 2, 3 and 4 are longitudinal sectional views of principal parts of devices for carrying out the steps of the instant method invention, the views showing the movable parts in different positions and showing a can -bodyin extending bead section B (Fig. 4) and two outwardly extending bead sections C, D of dierent sizes and closely adjacent the inside bead section B.

In forming these bead sections, the bead section B is ilrst produced by bending the metal side wall of the body inwardly while drawing a portion of the metal for the bead from the outer or adjacent end of the body (the right as viewed in Figs. l, 2, 3 and 4). This beading action also clamps the body adjacent the bead so produced at the conclusion of the beading operation and immediately following the outside beads C, D are formed by bending the body wall outwardly. The metal for these beads is drawn entirely from the opposite unclamped section of the body, i. e., from the central part where there is plenty of stock available. Therefore, since the stretched sections are not disturbed, as in ordinary operations, rupture between the two major beads B, D is prevented.

One form of apparatus for effecting these bead forming steps is shown in the drawing and includes a stationary mandrel I I on which the can body A is preferably supported while undergoing the beading operation. On the outer end of the mandrel there is located two sets of segmental beading or squeezing jaws I2 and I3 which are disposed side by side. The jaws are retained against endwise displacement by an end cap I4 which is held in place by long screws I5. 'I'he screws extend through the cap, through` grooves IE formed in the side edges of the `laws I2, I3 and are threaded into the inner end of the mandrel.

The outer edges of the jaws I2, I3.are curved and the jaws of each set are retained against radial displacement by endless coiled springs Il, I8, which pass around the curved surfaces of the jaws and hold the latter together. The springs are disposed in grooves I9 which are formed in the outer curved surfaces of the Jaws.

'Ihe outer curved surfaces of jaws I2 are formed with an inside bead groove 25. The curved surfaces of jaws I3 are formed with two raised outside beading sections 28,11.

The two sets of jaws I2, I3 surround a jaw expanding plunger 3| which is formed on a -stem 32 carried in a central longitudinal bore or slideway 33 located inside the mandrel Il. The outer end of the stem is connected to an operating lever 34 which may be actuated in any suitable manner to reciprocate the plunger 3I. For this purpose the plunger is formed with a pair of stepped cam surfaces 3B, 31 which are adapted to cooperate with stepped cam surfaces 38, 39 formed in the inner edge of jaws I2 and stepped cam surfaces 4I, 42 formed in the inner edge of jaws I3.

Extending around the outside of the can body A as it rests on the mandrel II, is a plurality of segmental outside jaws 45 which may be supported and actuated in any suitable manner. The inner edges 46 of these jaws are curved to fit around the can body wall. Along their curved edges, the jaws are formed with raised inside bead sections 41 for cooperation with the groove 25 of the inside jaws I2 and each jaw is also formed with a pair of outside bead grooves 48, 49 for cooperation with the raised bead sections on the jaws I3.

In operation the inside jaws I2 are first expanded by actuation of the plunger 3l moving toward the left as viewed in Fig. 1. This forces i the jaws I2 outwardly against the inside surface ol the can body A supported on the mandrel,

as shown in Fig. 2. While these jaws 2| are moving outwardly, the outside jaws 45 move in against the outside of the can body, thereby squeezing the wall of the body between them. In this action the bead sections 41 on the outside jaws 45 press the body Wall into the groove 25 of the inside Jaws I2 thus pulling the metal of the body inwardly from the outerv end lof the body, as viewed at the right in Fig. 3. It is this action that forms the inside bead B, constituted partly from the metal drawn inwardly from such outer end of the can body.

' The plunger 3i does not stop after a stroke is once started and during the second portion of the stroke expands the inside jaws i3 outwardly against the can body while the jaws I2, 45 hold the section which contains the bea'd B in a tightly clamped position. This outward movement of the jaws AI3 forces the raised bead sections 26, 21 against the wall of the body and thereby presses the body wall into the grooves 48, 4S of the outside jaws 45.

During this forming operation the metal for the outer beads is drawn entirely from the opposite or unclamped section of the body, this being taken from the central part of the body as here shown. It is this forming action that produces the outside beads C, D. This completes the bead forming operations and the plunger 3i thereupon moves back through a return stroke and hence allows the inside jaws I2, I3 to contract under their spring action. The outside jaws 5 are also drawn away from the mandrel therebyf freeing the beaded can body A so that it may be removed from the mandrel for subsequent operations.

In this manner lthe oppositely directed .beads B, C and D ,are thus formed in one operation by drawing the major portion of the metal for the beads from opposite sections of the can body. In so doing the beads or other equivalent structure may be formed in closely adjacent relation without rupturing the metal of the body between the beads since such metal section is not unduly stretched and restretched as is usual in multiple beading operations.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the steps of the process described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the process hereinbefore described being merely a prefererd embodimnt thereof.

I claim:

1. The method of forming adjacent bead sections in tubular can parts, comprising rigidly supporting the can part interiorly thereof while bending the can part material to form a bead therein by radially exerted opposed inward and outward pressure on opposite sides of the can part and drawing part of the stock material from one side of the formed bead, clamping the bead against movement, and immediately thereafter in the same beading movement bending 'the can part material to form a succeeding bead adjacent said first mentioned bead section by the application of further opposed radially exerted inward and outward pressure on opposite sides of the tubular can part while drawing the stock for said last mentioned bead from the can part material disposed on the opposite side of said lastmentioned bead, whereby to insure against unduly stretching and weakening the stock material between said beads.

2. vThe method of forming adjacent inside and outside bead sections in a can body, comprising supporting the can body while bending the wall of the can body inwardly by radially exerted opposed inward and outward pressure on opposite sides of the can body and drawing a part of the stock material from one end of the can body to produce an inwardly extending bead therein, clamping the bead so produced against movement, and immediately thereafter in the same beading movement bending the adjacent wall of the can body outwardly by the application of further opposed radially exerted inward and outward pressure on opposite sides of the can body to produce an outwardly extending bead therein disposed adjacent said inwardly extending bead section while drawing the stock material for said last mentioned bead from thev opposite end of the can body, whereby to insure against unduly stretching or weakening the can body material between said beads.

. JOI-1N M. HOTHERSALL. 

